Warp draw-off apparatus

ABSTRACT

A loom having a warp beam spaced from one end of the shed area and a cloth beam spaced from the other end of the shed area is provided with a first friction roll disposed between said warp beam and said area, a second friction roll disposed between said cloth beam and said area, a common drive shaft connected to each of said friction rolls by a worm wheel and a worm, a slipping friction clutch being operatively interposed between said first friction roll and the associated worm wheel. One of the worms can be coupled to said drive shaft in any of a plurality of relative angular positions which the loom is at a standstill.

United States Patent 1191 Filter Au 26 1975 [54] WARP DRAW-OFF APPARATUS 1,062,455 5/1913 Greenhalgh et al. 139/99 2,820,485 l/l958 Selles [75] Inventor g g Langenhageni 3,308,854 3/1967 Pfarrwallcr 139 99 erm ny FOREIGN PATENTS OR APPLICATIONS [73] Assignees: Vereinigte Osterreichische Eisen-und Stahlwerke Alpine Montan 393,386 6/1933 Umtcd Kingdom 139/99 Aktiengesellschaft, Vienna, Austria; Etablissement Wanderfield & Co., Primary Exammer j?'mes Kee Schaan, Liechtenstein Attorney, Agent, or F1rmKurt Kelman [22] F1led: May 13, 1974 ABSTRACT [211 App! 469384 A loom having a warp beam spaced from one end of the shed area and a cloth beam spaced from the other [30] Foreign Application Priorit D m end of the shed area is provided with a first friction May 16 1973 Austria 4264/73 disposed between Said warp beam and Said area a second friction roll disposed between said cloth beam 52 us. c1 139/99- 139/304 and said a comm drive Shaf connected 51 Int. c1. ..1)031) 49/06- 13031) 49/20 each of Said fYiCtiO mus by 3 whee and a 58 Field Of Search 139/99, 97, 100, 304, 307, won, a Slipping friction cluch being Perafively 139/308 105 terposed between said first friction roll and the associated worm wheel. One of the worms can be coupled to 56] References Cited said drive shaft in any of a plurality of relative angular UNITED STATES PATENTS positions which the loom is at a standstill. 676,376 6/1901 Whitchurst 130 99 3 Claims, 2 Drawing Figures WARP DRAW-OFF APPARATUS This invention relates to a warp draw-ofi apparatus for use in a loom having two beams, which respectively precede and succeed the shed area in the direction of warp movement.

In known looms the warp is tensioned between the driven warp beam and the driven cloth beam so that the entire driving force need not be applied by means of the cloth beam. The warp tension depends on the diameter of the material wound on each beam, unless additional tensioning means are provided.

In a known warp draw-off apparatus (US. Pat. No. 727,533), the warp beam and the cloth beam are connected by worm gearing to a common drive shaft, which extends transversely to the axes of said beams, and a friction clutch is provided between the cloth beam and the worm wheel associated therewith to prevent a change in tension with changes in beam diameter.

In the known arrangement, the warp tension cannot be adjusted while the machine is being set up because the warp is not tensioned unless the machine is in operation so that variations in warp tension are unavoidable at least at the beginning of the weaving operation.

It is an object of the invention so to improve a warp draw-off apparatus of the kind described that a constant warp tension can be achieved with simple means and a desired initial warp tension can be established while the weaving machine is being set up.

This object is accomplished according to the invention in that draw-off rolls are (friction rolls) associated with the warp beam and the cloth beam, respectively, and that the worm of one of two worm gearings connecting the draw-off rolls to a common drive shaft may be coupled to the shaft in different relative angular positions, while the draw-off apparatus is at a standstill. This arrangement has the advantage that the warp tension is independent of the diameter of the material on the warp beam and cloth beam because the warp is drawn off by separate rolls. During setting up of the loom a desired initial tension of the warp threads may be established by turning the worm of one of the two worm gearings relative to the drive shaft. The warp tension may also be adjusted at a slipping friction clutch between one of the draw-off rolls and the associated worm wheel by setting the maximum torque which can be transmitted; by the friction clutch.

An embodiment of the invention is shown by way of example in the accompanying drawings, in which FIG. 1 is a side elevation of warp draw-off apparatus according to the invention and FIG. 2 shows clutch discs in the apparatus of FIG. 1 in front elevation.

A cloth draw-off roll 1 which precedes a cloth beam 13 in the direction of warp movement and awarp drawoff roll 2 which succeeds a warp beam 14 and is referred to hereinafter as a back rest, are connected to a hollow shaft and a drive shaft 6, respectively, by a worm 3 and a worm wheel 4. .The drive shaft 6 is associated with the back rest 2 and passes coaxially through the hollow shaft 5. Adjacent axial ens of the hollow shaft 5 and the drive shaft 6 carry respective coupling discs 7 and 8.

A slipping friction clutch 9 is provided between the back rest 2 and the worm wheel 4 and limits tension in the warp 16. The friction clutch 9 permits adjustment of the maximum transmitted torque.

An intermittent drive actuates the shafts 5, 6 by means of a disc 10 secured against rotation on the shaft When it is desired to adjust the initial warp tension in the shed 15 while the loom is being set up the discs 7, 8 coupling the two shafts 5, 6 to each other are disengaged, and one of the two shafts is rotated relative to the other. Because the cloth draw-off roll and the back rest 2 are provided with friction coverings which prevent a slipping of the warp threads, the latter may be tensioned by turning the cloth draw-off roll 1 and the back rest 2 relative to one another. As the .worm gearings are self-locking, the frictions rolls 1, 2 do not require locking devices.

To permit a connection of the two coupling discs 7 and 8 in a very large number of relative angular positions, each disc is formed with a different number of bores 11, uniformly spaced on respective circles of equal diameter for receiving a coupling pin 12. To establish a warp tension adjusted by relative rotation of the two coupling discs, it is sufficient to select a bore which is aligned as exactly as possible with a bore in the other disc and insert the coupling pin through the aligned bores.

What is claimed is:

1. In a loom having a shed area and comprising a warp beam spaced from one end of said area, a cloth beam spaced from the other end of said area, and warp draw-off apparatus; the improvement in the warp drawoff apparatus comprising a. a first friction roll disposed between said warp beam and said area,

b. a second friction roll disposed between said cloth beam and said area,

r c. a drive shaft extending transversely to the axes of said first and second friction rolls,

d. two worm gearings respectively associated with said friction rolls and each including a worm wheel operatively connected to the associated friction roll and a worm nonrotatably connected to said drive shaft and meshing with said worm wheel,

e. a friction clutch connecting said first friction roll and the associated warm wheel, and

. f. coupling means for coupling the worm of one of said worm gearings to said drive shaft in each of a plurality of relative angular positions while said apparatus is at a standstill.

2. In a loom as set forth in claim 1, said coupling means including a hollow shaft coaxially surrounding said drive shaft and having an end axially adjacent to an end of said drive shaft, and two coupling discs respectively carried by said adjacent ends, said worm of said one worm gearing being mounted on said hollow shaft. I

3. In a loom as set forth in claim 2, each of said coupling discs being formed with a plurality of axial bores uniformly spaced along a circle, and the number of bores in one of said discs differing from the number of bores in the other disc, said coupling means further including a coupling pin detachably extending through respective, axially aligned bores in said two discs. 

1. In a loom having a shed area and comprising a warp beam spaced from one end of said area, a cloth beam spaced from the other end of said area, and warp draw-off apparatus; the improvement in the warp draw-off apparatus comprising a. a first friction roll disposed between said warp beam and said area, b. a second friction roll disposed between said cloth beam and said area, c. a drive shaft extending transversely to the axes of said first and second friction rolls, d. two worm gearings respectively associated with said friction rolls and each including a worm wheel operatively connected to the associated friction roll and a worm nonrotatably connected to said drive shaft and meshing with said worm wheel, e. a friction clutch connecting said first friction roll and the associated warm wheel, and f. coupling means for coupling the worm of one of said worm gearings to said drive shaft in each of a plurality of relative angular positions while said apparatus is at a standstill.
 2. In a loom as set forth in claim 1, said coupling means including a hollow shaft coaxially surrounding said drive shaft and having an end axially adjacent to an end of said drive shaft, and two coupling discs respectively carried by said adjacent ends, said worm of said one worm gearing being mounted on said hollow shaft.
 3. In a loom as set forth in claim 2, each of said coupling discs being formed with a plurality of axial bores uniformly spaced along a circle, and the number of bores in one of said discs differing from the number of bores in the other disc, said coupling means further including a coupling pin detachably extending through respective, axially aligned bores in said two discs. 